Solid-state lighting (SSL) apparatus have semiconductor structures that emit light. Examples of SSL lighting include light-emitting diodes (LEDs), semiconductor laser diodes (LDs), organic light-emitting diodes (OLED), polymer light-emitting diodes (PLED), or quantum dots. Individual LEDs, LDs, OLEDs, PLEDs, and quantum dots may be referred to as “SSL elements.” SSL is becoming more popular due in part to the energy efficient qualities and durability of SSL. One popular application is advertising and public information signage. In some implementations, LEDs are placed along one or more edges of a light-transmitting panel, and the light-transmitting panel is configured to evenly distribute light emitted from the LEDs through a surface of the panel.
With an edge-lit panel, light from the LEDs is spread evenly through the panel by total internal reflection. Disruptions formed on the surface of the panel scatter incident light so that light is emitted from the surface of the panel.